-# frexp.m4 serial 7
-dnl Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+# frexp.m4 serial 11
+dnl Copyright (C) 2007-2011 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_FREXP],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_REQUIRE([gl_CHECK_FREXP_NO_LIBM])
FREXP_LIBM=
- AC_CACHE_CHECK([whether frexp() can be used without linking with libm],
- [gl_cv_func_frexp_no_libm],
- [
- AC_TRY_LINK([#include <math.h>
- double x;],
- [int e; return frexp (x, &e) > 0;],
- [gl_cv_func_frexp_no_libm=yes],
- [gl_cv_func_frexp_no_libm=no])
- ])
if test $gl_cv_func_frexp_no_libm = no; then
AC_CACHE_CHECK([whether frexp() can be used with libm],
[gl_cv_func_frexp_in_libm],
[
save_LIBS="$LIBS"
LIBS="$LIBS -lm"
- AC_TRY_LINK([#include <math.h>
- double x;],
- [int e; return frexp (x, &e) > 0;],
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ double x;]],
+ [[int e; return frexp (x, &e) > 0;]])],
[gl_cv_func_frexp_in_libm=yes],
[gl_cv_func_frexp_in_libm=no])
LIBS="$save_LIBS"
if test $gl_func_frexp = yes; then
AC_DEFINE([HAVE_FREXP], [1],
[Define if the frexp() function is available and works.])
- else
- AC_LIBOBJ([frexp])
fi
AC_SUBST([FREXP_LIBM])
])
AC_DEFUN([gl_FUNC_FREXP_NO_LIBM],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
- AC_CACHE_CHECK([whether frexp() can be used without linking with libm],
- [gl_cv_func_frexp_no_libm],
- [
- AC_TRY_LINK([#include <math.h>
- double x;],
- [int e; return frexp (x, &e) > 0;],
- [gl_cv_func_frexp_no_libm=yes],
- [gl_cv_func_frexp_no_libm=no])
- ])
+ AC_REQUIRE([gl_CHECK_FREXP_NO_LIBM])
if test $gl_cv_func_frexp_no_libm = yes; then
gl_FUNC_FREXP_WORKS
case "$gl_cv_func_frexp_works" in
if test $gl_func_frexp_no_libm = yes; then
AC_DEFINE([HAVE_FREXP_IN_LIBC], [1],
[Define if the frexp() function is available in libc.])
- else
- AC_LIBOBJ([frexp])
fi
])
+dnl Test whether frexp() can be used without linking with libm.
+dnl Set gl_cv_func_frexp_no_libm to 'yes' or 'no' accordingly.
+AC_DEFUN([gl_CHECK_FREXP_NO_LIBM],
+[
+ AC_CACHE_CHECK([whether frexp() can be used without linking with libm],
+ [gl_cv_func_frexp_no_libm],
+ [
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ double x;]],
+ [[int e; return frexp (x, &e) > 0;]])],
+ [gl_cv_func_frexp_no_libm=yes],
+ [gl_cv_func_frexp_no_libm=no])
+ ])
+])
+
dnl Test whether frexp() works also on denormalized numbers (this fails e.g. on
dnl NetBSD 3.0), on infinite numbers (this fails e.g. on IRIX 6.5 and mingw),
dnl and on negative zero (this fails e.g. on NetBSD 4.99).
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works],
[
- AC_TRY_RUN([
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
#include <float.h>
#include <math.h>
#include <string.h>
+/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
+ ICC 10.0 has a bug when optimizing the expression -zero.
+ The expression -DBL_MIN * DBL_MIN does not work when cross-compiling
+ to PowerPC on MacOS X 10.5. */
+#if defined __hpux || defined __sgi || defined __ICC
+static double
+compute_minus_zero (void)
+{
+ return -DBL_MIN * DBL_MIN;
+}
+# define minus_zero compute_minus_zero ()
+#else
+double minus_zero = -0.0;
+#endif
int main()
{
+ int result = 0;
int i;
volatile double x;
-/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
- So we use -zero instead. */
double zero = 0.0;
/* Test on denormalized numbers. */
for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
/* On machines with IEEE754 arithmetic: x = 1.11254e-308, exp = -1022.
On NetBSD: y = 0.75. Correct: y = 0.5. */
if (y != 0.5)
- return 1;
+ result |= 1;
}
/* Test on infinite numbers. */
x = 1.0 / 0.0;
int exp;
double y = frexp (x, &exp);
if (y != x)
- return 1;
+ result |= 2;
}
/* Test on negative zero. */
- x = -zero;
+ x = minus_zero;
{
int exp;
double y = frexp (x, &exp);
if (memcmp (&y, &x, sizeof x))
- return 1;
+ result |= 4;
}
- return 0;
-}], [gl_cv_func_frexp_works=yes], [gl_cv_func_frexp_works=no],
- [case "$host_os" in
- netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";;
- *) gl_cv_func_frexp_works="guessing yes";;
- esac
- ])
+ return result;
+}]])],
+ [gl_cv_func_frexp_works=yes],
+ [gl_cv_func_frexp_works=no],
+ [case "$host_os" in
+ netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";;
+ *) gl_cv_func_frexp_works="guessing yes";;
+ esac
+ ])
])
])